Apparatus for slitting sheet metal

ABSTRACT

A process and apparatus for slitting sheet metal having a plurality of inflatable fluid passageways therein into strips, each having at least one inflatable fluid passageway which comprises providing sheet metal having at least two sheets pressure welded together in some areas and having a plurality of unwelded areas corresponding to inflatable passageways. The sheet metal contains at least one unwelded area extending within it in a predetermined fixed relationship to the remaining unwelded area, this one unwelded area being a control tube for use in aligning the sheet metal for slitting. The aligning of the sheet metal is achieved by passing it about a locater mandrel which plows open the control tube and fixes the position of the sheet as it enters the slitting assembly. The sheet metal as thus aligned then proceeds into a conventional slitting assembly wherein it is cut into strips. The locater mandrel may be fixed or may be provided with means for adjusting its position relative to the slitting assembly. A second slitting assembly may be employed ahead of the locater mandrel whose purpose is to remove a portion of the strip containing part of the control tube.

United States Patent [1 1 Keith [45] Jan. 30, 1973 [54] APPARATUS FORSLITTING SHEET METAL [76] Inventor: Norval A. Keith, 171 ClearviewStreet, East Alton, Ill.

[22] Filed: July 26, 1971 [21] Appl. No.: 166,267

Related US. Application Data [62] Division of Ser. No. 5,548, Jan. 26,1970.

[52] US. Cl. .83/I, 83/425, 83/442, 83/444, 83/448, 83/925 R [51] Int.Cl. ..B26d 1/02, B26d 3/00, B26d 9/00 [58] Field of Search....r83/425,1,442, 444, 448, 925 R; 29/4709 [56] References Cited UNITED STATESPATENTS 2,452,3l2 10/1948 McMurray ..83/444 X 2,831,209 4/1958 Bergmanet al ..83/444 X 3,l2l,950 2/l964 Maier et al. ..29/470.9 X

Primary Examiner Frank T. Yost Attorney Robert H. Bachman and Gordon G.Men- [57] ABSTRACT A process and apparatus for slitting sheet metalhaving a plurality of inflatable fluid passageways therein into strips,each having at least one inflatable fluid passageway which comprisesproviding sheet metal having at least two sheets pressure weldedtogether in some areas and having a plurality of unwelded areascorresponding to inflatable passageways. The sheet metal contains atleast one unwelded area extending within it in a predetermined fixedrelationship to the remaining unwelded area, this one unwelded areabeing a control tube for use in aligning the sheet metal for slitting.The aligning of the sheet metal is achieved by passing it about alocater mandrel which plows open the control tube and fixes the positionof the sheet as it enters the slitting assembly. The sheet metal as thusaligned then proceeds into a conventional slitting assembly wherein itis cut into strips. The locater mandrel may be fixed or may be providedwith means for adjusting its position relative to the slitting assembly.A second slitting assembly may be employed ahead of the locater mandrelwhose purpose is to remove a portion of the strip containing part of thecontrol tube.

7 Claims, 14 Drawing Figures I PATENTEUJAHO ms sum 1 BF 2 NORVAL ,4vKEITH mi {11% INVENTOR ATTORNEY PATENTEDJAN 30 I975 SHEET 2 [1F 2 FIG-5avg,

INVENTOR NORVAL A. KEITH mwomuzv FIG -8 APPARATUS FOR SLITTING SHEETMETAL This application is a division of copending application Ser. No.5,548, filed Jan. 26, 1970.

In the manufacture of sheet metal tubing from continuous strip havinginflatable fluid passageways, it is most economical to produce thematerial in a wide coil form which can later be slit into strips of thedesired width. It is extremely difficult to slit this type of coilwithout cutting into one or more of the tube patterns. This is the casesince the patterns must be close together from the standpoint ofeconomy. The distance between the respective tube patterns and the edgeof the coil is not consistant enough to enable one to use the edge ofthe coil as a slitting reference surface. Accuracy in the range of 0.005inch to 0.010 inch is necessary when slitting this type of coil. Thetube pattern edge to slit edge dimensional tolerances are not obtainablewhen using the prior art techniques which use the edge of the coil as areference surface.

This invention has been devised to obtain the desired accuracy byproviding a control tube pattern in the coil for guiding purposes. Thedummy or control tube pattern is located in the coil in a fixedrelationship to the other tube patterns so the coil can beaccuratelyaligned with the slitter to cut the individual strips from it.In order to maintain the desired accuracy during slitting, in accordancewith this invention, a locater mandrel is so designed that as the coilpasses about it, the control tube is slit and plowed open, therebyproviding the desired alignment of the coil as it enters the slittingassembly. The mandrel is stationary, as are the slitter knives, thus thecoil is moved to align it with the slitter knives.

In the past, slitting of coils of the type useful with this invention,was accomplished by guiding them using their edges as the referencesurface. This cannot produce the desired accuracy because the edge ofthe coil does not necessarily accurately follow the tubular patternswithin the coil. The instant invention avoids this problem by patterninga control tube simultaneously with the working tube pattern so that anaccurately fixed relationship is always maintained for reference duringslitting.

It is accordingly an object of this invention to provide an apparatusfor slitting sheet metal coils having a plurality of patterns ofuninflated fluid passageways into strips, each having at least oneinflatable fluid.

passageway.

It is a further object of this invention to provide an apparatus forslitting these coils in an accurate manner which will avoid cutting intothe tubular patterns within each strip.

It is a further object of this invention to provide a sheet metal coilcomprising at least two sheets of metal bonded together in some areasand having other areas forming patterns of inflatable fluid passagewaysand further including a control tube for reference during slitting.

It is a further object of this invention to provide a process foraccurately slitting a sheet metal coil having a plurality of patterns ofuninflated fluid passageways, into a plurality of strips each of whichcontains at least one inflatable passageway.

Other objects and advantages will become apparent from the followingdescription and drawings, in which:

FIG. 1 shows a perspective view of a portion of a sheet metal coil inaccordance with this invention. FIG. 2 shows an edge view of a coil asin FIG. 1.

FIG. 3 shows an edge view of an inflated strip.

FIG. 4 shows a perspective view of one embodiment of an apparatus inaccordance with this invention.

FIG. 5 showsa front view of an apparatus as in FIG. 4.

FIGS. 6A and 6B shows the front and side views of a locater mandrel inaccordance with this invention.

FIG. 7 shows a perspective view of a locater mandrel in accordance withthis invention.

FIG. 8 shows a view of a locater mandrel in plowing contact with a coil.

FIG. 9 shows a partial edge view of the coil in accordance with thisinvention immediately after passing the locater mandrel of FIG. 7.

FIG. 10 shows a perspective view of a preferred apparatus in accordancewith this invention.

FIG. 11 shows a perspective view of a preferred locater mandrel for usein the preferred apparatus in FIG. 10.

FIG. 12 shows a partial edge view. of the coil immediately after passingthe locater mandrel of FIG. 1 1.

FIG. 13 shows a perspective view of a pressure roller useful with theapparatus of FIG. 10.

Referring now to the drawings and especially to FIG. I, there isillustrated a portion of a coil 1 exemplary of the type of coiled sheetuseful in this invention. The coiled sheet with which this invention maybe used may be fabricated by the method disclosed in U.S. Pat. No.2,690,002 granted to Grenell on Sept. 28, 1954. For example, referringto FIG. 1, a pattern of weld inhibiting or stop-weld material 2 isapplied to a clean surface of a sheet of metal 3. The stop-weld pattern2 comprises a plurality of individual patterns laid out inlongitudinally extending strip areas 4. It further includes at least onecontrol tube pattern 5 extending longitudinally in the sheet and whichis in a fixed relationship to the other patterns 2. This control tubepattern 5 provides the reference line for slitting. The other patternsof stop-weld 2 provide the inflatable fluid passageways in the stripwhich is slit from the sheet metal coil. A second sheet 6 of metalhaving a clean surface is superimposed on the surface of the first sheet3 having the stop-weld pattern, and the two sheets 3 and 6 are securedtogether to prevent relative motion therebetween. Thereafter, the twosuperimposed sheets 3 and 6 are pressure welded together by rolling, sothat the adjacent areas 7 of the sheets 3 and 6 which are not separatedby stop-weld 2 and 5 become bonded together. The rolling of the sheets 3and 6 results in reducing their thickness and in elongating theresultant sheet I in the direction of rolling. The width of theresultant sheet 1 remains substantially the same as the initial width ofthe sheets 3 and 6. Following the rolling operation, the resultant sheet1 is usually softened as by annealing to make it more pliable. Ifdesired, it may be further rolled to the final gage and again softenedas by annealing.

The stop-weld material 2 and 5 results in the reten-. tion of unweldedportions 8, as shown in FIG. 2, cor responding to the stop-weld pattern2 and 5 which is sandwiched between the outer surfaces of the resultantsheet 1. After softening this sheet and slitting it into strips 9, theunjoined portions are usually expanded as in FIG. 3 to form the desiredpassageways 10. This expansion is obtained by injecting a fluid, such asair or water, into the unjoined portions 8 under a pressure ofsufficient magnitude, to permanently deform the sheet metal in that areaso as to form the passageways 10.

It is to be understood, however, that other methods may be employed inthe manufacture of the strips 9 used with this invention. Forconvenience in shipping and packaging, the resulting sheet 1 having theplurality of patterns 2 and is put in coil form, however, the inventionis applicable to sheets 1 of varying lengths whether coiled or flat.

As noted above, the coil in accordance with the instant inventioncontains a plurality of stop-weld patterns 2 each of which lies within alongitudinal strip area 4 of the sheet metal 1. It is the object of thisinvention to slit the coil into strips 9 corresponding to the areas 4.In practice, the stop-weld patterns 2 for each strip area may beseparated from each other by about 0.050 inch to 0.100 inch so that aslitting tolerance of 0.005 inch to 0.010 inch is desired though notobtainable by previous techniques. Although the stop-weld patterns maybe laid out initially in accurate alignment with the edge of the sheetmetal 1, the rolling operation required for bonding as above noted tendsto distort this relationship. Thus, there is the necessity for the hightolerance noted.

It has been found that in use, a control tube pattern 5, one-fourth inchto five-eighths inch in width is practical and that the tolerance of thepattern 5 as deposited should be in the range of i 0.002 inch andpreferably 0.001 inch. The strips 9 which are cut from the sheet metal Inormally vary from threefourths inch in width to as much as 3 mo inch. Awidth of 1% inch is often used in practice.

Referring now to FIG. 4, there is shown an apparatus in accordance withthis invention. The apparatus comprises a frame to which is mounted aslitting assembly 21. The slitting'assembly 21 comprises rotatingslitting knives 22 which are arranged as shown in FIG. 5 to cut thesheet metal 1 into strips 9 of the desired width. The knives 22 arepowered by means of a motor, not shown. The apparatus also includesmeans for holding a sheet metal coil 23 and for supplying sheet metal 1to the slitting knives 22 and a locater mandrel 24 which is in fixedspacial relationship to the slitting knives 22. As the sheet metal 1from the coil is fed past the locater mandrel 24,'the control tube 5 isplowed open, thereby accurately fixing the alignment of the sheetmetal las it passes into the slitting assembly 21. As the sheet passes throughthe slitting assembly 21, the portion with the control tube 5 is cut offand discarded as scrap and the remainder of the coil is cut into strips9. The strips 9 each contain at least one stopweld pattern and are againcoiled, (not shown), for further processing.

The shape of the locater mandrel 24 is extremely important in thisinvention. Referring to FIGS. 6A and 68, there is shown a typicallocater mandrel 24 for use in the apparatus shown in FIG. 4 wherein thecontrol tube 5 is to be fully plowed out. The mandrel 24 has a 25 andwhich meet at 27 to form the plowing surface.

. The inclined portions are more readily discemable from FIG. 7 whichshows the overall shape of the mandrel 24. As shown in FIG. 7, there arefour inclined faces A, B, C and D in the inclined portion 26. The fronttwo A and B are angled with respect to each other, so that they meetalong line 27 and provide plowing action when the mandrel 24 engages thecontrol tube 5. The side faces C and D provide the guiding function forthe mandrel 24 as they accurately ride within the control tube 5. Themandrel also includes a shaft portion 28 which has sides 29 and faces Eand F forming a V-shaped front portion 30. The V-shaped front portion 30functions to cut open the top sheet 6 of the control tube 5 so that theshaft portion 28 may pass through the control tube, while the inclinedportion 26 rides within the control tube, plowing it open.

This is best shown in FIG. 8 where the mandrel 24 is shown after theV-shaped portion 30 of the shaft 28 has cut the top sheet 6 of thecontrol tube 5 apart. As shown, the bottom portion 25 of the mandrel 24accurately fixes the alignment of the sheet 1 by substantially taking upthe control tube 5 area. The inclined faces A and B of the mandrel 24plow up the top sheet 6 and raise it out of the way, and after it is cutby the V- shaped portion 30, the mandrel may pass on in a continuousfashion. Therefore, the sheet 1 is aligned with the mandrel 24 throughthe contact between the bottom sheet 3 and the bottom 25 of the mandreland that between the cut apart top sheet 6 and the inclined portions Cand D of the mandrel.

Referring again to FIG. 7, the mandrel 24 also includes a mountingportion 31 which has holes 32 through which the locating bolts, (notshown), are placed to secure the mandrel 24 to the apparatus, shown inFIG. 4. The cutting surface of the mandrel may be curved as shown inFIG. 6A to enhance the plowing action and render the cutting easier.

FIG. 9 shows the sheet 1 after it has passed the mandrel 24 but beforeit has entered the slitting assembly 21. It can be seen that the controltube 5 is cut open at the top sheet 6 and that the top sheet is plowedapart by the plowing action of the mandrel 24.

While the apparatus in accordance with FIG. 4 provides the accuratelyalignment desired with this invention, there may be tool wear of thelocater mandrel 24 because it functions to both plow the tube 5 and tocut it open. Therefore, a preferred apparatus has been developed whereina portion of the control tube is first slit off the sheet 1 and then thesheet 1 is fed past a locater mandrel which merely plows apart the topsheet 6 of the remaining portion of the tube 5. A suitable apparatus forcarrying out this embodiment is shown in FIG. 10 and comprises a frame101 and a first slitting assembly 102. The. first slitting assembly ises sentially similar to that described with reference to FIG. 4 and willnot be discussed further. In this apparatus, there is a second slittingassembly 103 spaced ahead of the first slitting assembly 102 and aheadof the mandrel 100. This second slitting assembly 103 cuts off a portionof the control tube 5, usually about 1/2 its width. The sheet 1 thenproceeds to the locater mandrel 100 which plows apart the sheets 3 and 6of the control tube 5 as shown in FIG. 12. In order to provide forguiding the sheet 1, a pressure plate 104 or a roller assembly 105 asshown in FIG. 13, is used to maintain pressure against the edge 106 ofthe strip 1 so that it is pushed against the locater mandrel 100. Thepressure must be sufficient to push a strip against the locater mandrelwith sufficient force so that the mandrel 100 presses into the edge ofthe control tube 5 pattern until the edge of the mandrel substantiallyreaches the edge of the control tube 5.

The locater mandrel used in this apparatus is essentially similar to theone shown in FIG. 4 and a typical This means 110 for moving the mandrelmay also be incorporated in the apparatus of FIG. 4.

The sheet 1 is presses against the mandrel 100 by means of a springbiased plate assembly 104 which is connected to the frame 101. The plate114 exerts sufficient force by means of the spring 115 so that thecontrol tube 5 as it passes the mandrel 100, is plowed open tosubstantially the limit of the unbonded portion 5.

FIG. 12 shows the sheet 1 after passing the mandrel 100 but prior toslitting. It is seen from this figure that the control tube of whichabout one-half remains, is plowed open up to the limit of the stop-weldpattern 5. The force exerted by the spring biased plate assembly 104must be sufficient so that the mandrel 100 is plowing open the controltube 5 substantially up to the stopweld limit.

Alternatively, other means of applying pressure to the sheet 1 could beused, for example, in FIG. 13, there is shown a spring biased rollerassembly 105 which engages the edge 106 of the sheet 1 to provide therequisite pressure. The roller 116 is mounted to a top plate 117 whichis slidably mounted 118 to the frame. A spring 119 connected to the topplate 117 provides the pressure. Two pins 120 positioned within slots121 in the top plate 117 provide for the sliding movement of the topplate 117.

In operation then, the sheet 1 is fed from .the coil to the secondslitting assembly 103 which cuts off about one-half of the control tube5 and from there it passes about the locater mandrel 100 which plowsopen the control tube aligning the sheet 1 as it proceeds into the firstslitting assembly which cuts the sheet 1 into the desired strips 9. Theslitting rates may be substantially the same as those employed inconventional slitting operations.

While the locater mandrel has been described with respect to theembodiments shown in FIGS. 7 and 11, other shapes may be utilized withthis invention. It is essential that the mandrel fill out in some mannerthe control tube so as to provide accurate alignment. In the embodimentsof FIGS. 7 and 11, the flat bottom and inclined portions provide thisfunction. It is also possible to employ locater mandrels havingcylindrical shapes instead of the flat bottom and inclined portions 26.The cylindrical shapes may be either of circu- Iar cross section orelliptical cross section. The front portion of the cylinder would betapered in a conical fashion to substantially a point to provide theplowing action. The effect of a mandrel having this shape would besomewhat different to those previously described in that the bottomsheet 5 would also be deformed. In essence, the circular or ellipticalcross section would correspond to the shape of the control tube had itbeen inflated. The advantages of this type of tool over that disclosedwith reference to FIGS. 7 and 11 is that it decreases the possibility ofdigging into the bottom sheet 5. Mandrels employing the cylindrical typeplowing surface could still utilize the same type of shaft portion 28and mounting portion 24 as disclosed with reference to FIG. 7.

It has also been found that as the lead end section of the mandrelcorresponding to faces A and B in FIG. 7 is increased in length, thetendency to gaul or dig into the bottom sheet 5 is reduced.

The processes described above are applicable to any type of sheet metalwhich can be formed into the composite sheet described herein, andespecially to aluminum and aluminum alloys, copper, copper alloys andsteel. The strip 1 may be inflated as shown in FIGS utilizingconventional inflating pressures which generally vary over a range ofp.s.i. up to 3,000 p.s.i.

It is to be understood that the invention is not limited to theillustrations described and shown herein, which are deemed to be merelyillustrative of the best modes of carrying out the invention, and whichare suitable of modification of form, size, arrangement of parts anddetails of operation. The invention rather is intended to encompass allsuch modifications which are within its spirit and scope as defined bythe claims.

What is claimed is: 1. An apparatus for slitting sheet metal into aplurality of strips, wherein said sheet metal contains inflatable fluidpassageways with at least one passageway being a control tube, theapparatus comprising:

means contacting said sheet metal for slitting it into a plurality ofstrip; and

a-locater mandrel in a predetermined spaced relationship to saidslitting means, said locater mandrel being operative to align said sheetmetal with said slitting means, by contacting said sheet metal at saidcontrol tube and plowing said control tube open.

2. An apparatus as in claim 1 which includes means connected to saidlocater mandrel for adjusting its position relative to said slittingmeans.

3. An apparatus as in claim 2 wherein said locater mandrel comprises atool having a flat bottom, said flat bottom having a width slightly lessthan the width of said control tube, an inclined portion emanating fromsaid bottom comprising four faces with two of the faces angled towardeach other such that they meet along a line and with the remaining twofaces being substantially parallel, and a shaft portion emanating fromsaid inclined portion which includes means for cutting open said controltube.

4. An apparatus as in claim 1 which includes a second slitting meanspositioned ahead of said first slitting means and said locater mandrel,said second slitting means contacting said sheet metal and beingoperative to cut off a portion of said control tube.

5. An apparatus as in claim 4 which includes means contacting said sheetmetal for applying pressure to it as it passes about said locatermandrel.

6. An apparatus as in claim 5 which includes means 7. An apparatus as inclaim 6 wherein said locater mandrel comprises a flat bottom, aninclined portion emanating from said flat bottom having two faces withone face angled with respect to the other and a shaft connected to saidlocater mandrel for changing its posi- 5 portion emanating from saidinclined P tion with respect to said first slitting means.

1. An apparatus for slitting sheet metal into a plurality of strips,wherein said sheet metal contains inflatable fluid passageways with atleast one passageway being a control tube, the apparatus comprising:means contacting said sheet metal for slitting it into a plurality ofstrip; and a locater mandrel in a predetermined spaced relationship tosaid slitting means, said locater mandrel being operative to align saidsheet metal with said slitting means, by contacting said sheet metal atsaid control tube and plowing said control tube open.
 1. An apparatusfor slitting sheet metal into a plurality of strips, wherein said sheetmetal contains inflatable fluid passageways with at least one passagewaybeing a control tube, the apparatus comprising: means contacting saidsheet metal for slitting it into a plurality of strip; and a locatermandrel in a predetermined spaced relationship to said slitting means,said locater mandrel being operative to align said sheet metal with saidslitting means, by contacting said sheet metal at said control tube andplowing said control tube open.
 2. An apparatus as in claim 1 whichincludes means connected to said locater mandrel for adjusting itsposition relative to said slitting means.
 3. An apparatus as in claim 2wherein said locater mandrel comprises a tool having a flat bottom, saidflat bottom having a width slightly less than the width of said controltube, an inclined portion emanating from said bottom comprising fourfaces with two of the faces angled toward each other such that they meetalong a line and with the remaining two faces being substantiallyparallel, and a shaft portion emanating from said inclined portion whichincludes means for cutting open said control tube.
 4. An apparatus as inclaim 1 which includes a second slitting means positioned ahead of saidfirst slitting means and said locater mandrel, said second slittingmeans contacting said sheet metal and being operative to cut off aportion of said control tube.
 5. An apparatus as in claim 4 whichincludes means contacting said sheet metal for applying pressure to itas it passes about said locater mandrel.
 6. An apparatus as in claim 5which includes means connected to said locater mandrel for changing itsposition with respect to said first slitting means.